"PHILOSOPHICALLY SPEAKING...":

This fascinating essay reexamines the conviction of the short-lived Victorian mathematician and philosopher William Kingdon Clifford that "it is wrong always, everywhere, and for anyone, to believe anything upon insufficient evidence."

"In ‘The Ethics of Belief’ (1877), Clifford gives three arguments as to why we have a moral obligation to believe responsibly, that is, to believe only what we have sufficient evidence for, and what we have diligently investigated. His first argument starts with the simple observation that our beliefs influence our actions. Everyone would agree that our behaviour is shaped by what we take to be true about the world – which is to say, by what we believe. ... False beliefs about physical or social facts lead us into poor habits of action that in the most extreme cases could threaten our survival. ... As social animals, our agency impacts on those around us, and improper believing puts our fellow humans at risk. ... In a world in which just about everyone’s beliefs are instantly shareable, at minimal cost, to a global audience, every single belief has the capacity to be truly consequential in the way Clifford imagined. If you still believe this is an exaggeration, think about how beliefs fashioned in a cave in Afghanistan lead to acts that ended lives in New York, Paris and London. ... In the digital global village that we now inhabit, false beliefs cast a wider social net, hence Clifford’s argument might have been hyperbole when he first made it, but is no longer so today.

"The second argument Clifford provides to back his claim that it is always wrong to believe on insufficient evidence is that poor practices of belief-formation turn us into careless, credulous believers. ... Translating Clifford’s warning to our interconnected times, what he tells us is that careless believing turns us into easy prey for fake-news pedlars, conspiracy theorists and charlatans. And letting ourselves become hosts to these false beliefs is morally wrong because, as we have seen, the error cost for society can be devastating.

"Clifford’s third and final argument as to why believing without evidence is morally wrong is that, in our capacity as communicators of belief, we have the moral responsibility not to pollute the well of collective knowledge. ... Subverting this ‘heirloom’ [of collective knowledge], as he called it, by adding false beliefs is immoral because everyone’s lives ultimately rely on this vital, shared resource. ... Add the wrong ingredients into the Big Data recipe, and what you’ll get is a potentially toxic output. If there was ever a time when critical thinking was a moral imperative, and credulity a calamitous sin, it is now."
aeon.co/ideas/believing-without-evidence-is-always-morally-wrong